The Influence of Different Dietary Status on the Acute Responses to Exercise

Pre-trial assessments

V̇O2max measurement V̇O2max was determined using an incremental continuous treadmill test until the point of volitional exhaustion. For most participants, a treadmill speed of 4 km/h and gradient of 8.5% was chosen. Participants were tested at this speed and gradient with the speed increased by 1 km/h after every 3 min stage. One minute expired air samples were collected into Douglas bags (Douglas Bags, Hans Rudolph, MO, USA), and RPE and heart rates were measured in the final minute of each stage and also at the point of volitional exhaustion, defined as when the participant indicated that only 1 min remained until fatigue. Samples were analysed for relative expired fractions of oxygen and carbon dioxide gas (Servomex, Crowborough, UK) and the total volume with in the bag was measured using a dry gas meter (Harvard Apparatus, Kent, UK).

Physical activity assessment Participants wore a combined heart rate/accelerometer monitor for one week to assess their habitual physical activity energy expenditure (Actiheart, Cambridge Neurotechnology Ltd., Cambridge, UK). This was attached to the left chest via 2 adhesive ECG pads for 24 hours per day except for during showering/bathing/swimming.

Body composition analysis Body mass was measured using digital scales post-void (TANITA corp., Tokyo, Japan). Waist and hip circumference was assessed according to World Health Organisation guidelines. Body composition was determined using Dual energy X-ray absorptiometry (Discovery, Hologic, Bedford, UK). Abdominal subcutaneous and visceral adipose tissue mas was estimated from a central region between L1-L4.

Trial days In the 72 h prior to each main trial, participants were asked to refrain from performing any strenuous physical activity and from consuming alcohol/caffeine for 48 h prior to the main trials. A dietary record was completed 48 h before the first main trial and participants were asked to replicate this diet prior to their second main trial.